1. Field of the Invention
The present invention relates, generally, to golf course maintenance equipment, more particularly to equipment used to maintain sand traps, or bunkers on a golf course.
2. Background Information
A golf course has specific course features of greens, fairways, and sand traps or bunkers along with many natural features including hills, creeks, lakes, and trees. Each of these course features must be maintained in a meticulous, consistent manner. Greens must be of a particular type of grass that is mowed short and rolled smooth. Fairway grass should be uniform height and thickness, rough should be just that--rough. Bunkers must be of the proper density and texture. All these facilities should be kept clear of leaves and other debris.
As a result of these exacting maintenance requirements and the large scale of the jobs, a number of specialized machines have been developed to perform specific tasks. There are numerous turf mowers and rollers, leaf sweepers and bunker rakes, all intended to help meet the requirements of a particular maintenance task.
One particular machine is the bunker rake. The sand in a bunker or sand trap should have a certain firmness, and the surface should have a particular uniform texture. This is accomplished by a using a vehicle generally resembling a garden tractor which has the bunker rake attached to the rear of it. To rake a bunker, the bunker rake is lowered and pulled along the sand behind the vehicle. When the vehicle travels from one bunker to another the rake is raised to clear the ground.
Vehicles currently used to rake bunkers typically have internal combustion engines as a source of power and hydrostatic systems or mechanical drive systems to power the ground engaging wheels. Such machines have significant disadvantages.
For example internal combustion engines are inherently noisy. Golfers or golf course neighbors can be disturbed by machines with internal combustion engines. Golf courses are typically busy from early morning until dusk, so opportunities to use machines with internal combustion engines on a golf course without disturbing golfers are typically very early morning or very late evening. Using such equipment at those hours, however, may disturb golf course neighbors. Consequently, someone may always be disturbed by equipment powered by an internal combustion engine. Internal combustion engines also inherently produce emissions from burning hydrocarbon fuels. Such emissions pollute the air and are obnoxious to people in the vicinity of an operating machine. Internal combustion engines also need periodic maintenance to change lubricating oil and tune the engine.
Another problem with these machines, particularly those using hydrostatic drives, is that they have the potential to leak or spill fuel, lubricating oil, or hydraulic fluid which can damage a golf course green or fairway, or contaminate a bunker. A spill of such fluids into a bunker would soak a significant amount of sand which would have to be removed and disposed of as hazardous waste. Machines with hydrostatic drive require periodic leak checks of the hydraulic hoses and connections, as well as frequent checking and topping off levels of hydraulic fluid. Machines without hydrostatic drive also require significant maintenance of the drive mechanism, such as adjusting or replacing belts, chains, pulleys, or sprockets.
The above problems apply to all machines used for golf course maintenance. Another problem pertains specifically to bunker rakes. To achieve the proper surface finish on the sand in the bunker, the rake must be dragged on the sand at a certain speed which is relatively slow. But because there are many sand traps on a golf course, and they are often far apart, the tractor vehicle with an internal combustion engine typically has at least one faster speed to save time in traveling between bunkers. The problem arises when the operator uses the fast speed when raking the bunker. Dragging the bunker rake too fast makes the surface too irregular. This is a common occurrence, especially when the operators of these vehicles tend to be young and or seasonal employees who may not appreciate the need for the slow speed in the bunker. While golf course maintenance supervisors can properly train a young employee and tell them the importance of driving slow when raking bunkers, it has proven difficult to curb the tendency of employees to drive fast in the bunkers.
One solution to this problem for vehicles using a hydrostatic drive is described in applicants' assignee's U.S. patent application Ser. No. 08/726,903 titled Speed Limiting Device for Utility Vehicles, filed on Oct. 7, 1986. The above application is hereby incorporated by reference. Another solution to that problem, and to the problems stated above, is provided by the applicants' invention which uses an electric drive in a vehicle for raking bunkers.
Accordingly, it is an object of the present invention to provide a riding bunker rake which uses an electric motor as a prime mover.
It is a further object of this invention to provide a riding bunker rake which uses electric power to raise and lower an attached rake assembly.
It is another object of this invention to provide a riding bunker rake with a limited maximum speed that is not fast enough to improperly groom bunkers.
It is another object of this invention to provide a riding bunker rake which has electronic regenerative braking.